A casino is a facility for certain types of gambling. It is sometimes combined with hotels, resorts, restaurants, retail shops or cruise ships. A casino may also host live entertainment events. The precise origin of gambling is unknown, but it is believed to have originated in ancient Mesopotamia and was popularized by the Romans and Egyptians. In modern times, casinos are usually owned and operated by large corporations. Some are licensed and regulated by governmental authorities.

In most cases, casino customers gamble by playing games of chance or skill. In some games, such as poker, the house takes a commission (rake) on each hand played by a customer. The rake is often computed using mathematically determined odds that guarantee the house an advantage over players, known as the house edge. Casinos also offer complimentary items or comps to encourage gambling. In addition, the payout percentages of casino games are generally quite high, which attracts many gamblers.

Because of the large amount of money handled within a casino, both patrons and staff may be tempted to cheat or steal. Therefore, most casinos have strict security measures to prevent this from happening. These security measures may include the use of cameras located throughout the casino as well as rules requiring players to keep their hands visible at all times while playing card games. The security department of a casino is usually divided into a physical security force and a specialized surveillance department.